K201 improves aspects of the contractile performance of human failing myocardium via reduction in Ca2+ leak from the sarcoplasmic reticulum

In heart failure, intracellular Ca2+ leak from cardiac ryanodine receptors (RyR2s) leads to a loss of Ca2+ from the sarcoplasmic reticulum (SR) potentially contributing to decreased function. Experimental data suggest that the 1,4-benzothiazepine K201 (JTV-519) may stabilise RyR2s and thereby reduce detrimental intracellular Ca2+ leak. Whether K201 exerts beneficial effects in human failing myocardium is unknown. Therefore, we have studied the effects of K201 on muscle preparations from failing human hearts. K201 (0.3 μM; extracellular [Ca2+]e 1.25 mM) showed no effects on contractile function and micromolar concentrations resulted in negative inotropic effects (K201 1 μM; developed tension −9.8 ± 2.5% compared to control group; P < 0.05). Interestingly, K201 (0.3 μM) increased the post-rest potentiation (PRP) of failing myocardium after 120 s, indicating an increased SR Ca2+ load. At high [Ca2+]e concentrations (5 mmol/L), K201 increased PRP already at shorter rest intervals (30 s). Strikingly, treatment with K201 (0.3 μM) prevented diastolic dysfunction (diastolic tension at 5 mmol/L [Ca2+]e normalised to 1 mmol/L [Ca2+]e: control 1.26 ± 0.06, K201 1.01 ± 0.03, P < 0.01). In addition at high [Ca2+]e, K201 (0.3 μM) treatment significantly improved systolic function [developed tension +27 ± 8% (K201 vs. control); P < 0.05]. The beneficial effects on diastolic and systolic functions occurred throughout the physiological frequency range of the human heart rate from 1 to 3 Hz. Upon elevated intracellular Ca2+ concentration, systolic and diastolic contractile functions of terminally failing human myocardium are improved by K201

Immune status is prognostic for poor survival in colorectal cancer patients and is associated with tumour hypoxia

Background Immunohistochemical quantification of the immune response is prognostic for colorectal cancer (CRC). Here, we evaluate the suitability of alternative immune classifiers on prognosis and assess whether they relate to biological features amenable to targeted therapy. Methods Overall survival by immune (CD3, CD4, CD8, CD20 and FOXP3) and immune-checkpoint (ICOS, IDO-1 and PD-L1) biomarkers in independent CRC cohorts was evaluated. Matched mutational and transcriptomic data were interrogated to identify associated biology. Results Determination of immune-cold tumours by combined low-density cell counts of CD3, CD4 and CD8 immunohistochemistry constituted the best prognosticator across stage II–IV CRC, particularly in patients with stage IV disease (HR 1.98 [95% CI: 1.47–2.67]). These immune-cold CRCs were associated with tumour hypoxia, confirmed using CAIX immunohistochemistry (P = 0.0009), which may mediate disease progression through common biology (KRAS mutations, CRIS-B subtype and SPP1 mRNA overexpression). Conclusions Given the significantly poorer survival of immune-cold CRC patients, these data illustrate that assessment of CD4-expressing cells complements low CD3 and CD8 immunohistochemical quantification in the tumour bulk, potentially facilitating immunophenotyping of patient biopsies to predict prognosis. In addition, we found immune-cold CRCs to associate with a difficult-to-treat, poor prognosis hypoxia signature, indicating that these patients may benefit from hypoxia-targeting clinical trials

Mismatch repair status in patients with primary operable colorectal cancer: associations with the local and systemic tumour environment

BACKGROUND: Mismatch repair deficient (dMMR) colorectal cancer (CRC) is associated with a conspicuous local immune infiltrate, however its relationship with systemic inflammatory responses remains to be determined. The present study aims to examine the relationships and prognostic value of assessment of the local and systemic environment in the context of MMR status in patients with CRC. METHODS: The relationship between MMR status, determined using immunohistochemistry, and the local inflammatory cell infiltrate, differential white cell count, neutrophil:platelet score (NPS), neutrophil:lymphocyte ratio (NLR) and modified Glasgow Prognostic Score (mGPS), and cancer-specific survival was examined in 228 patients undergoing resection of stage I-III CRC. RESULTS: 35 patients (15%) had dMMR CRC. dMMR was associated with a higher density of CD3+, CD8+, CD45R0+ T-lymphocytes within the cancer cell nests, and an elevated mGPS (mGPS2: 23% vs. 9%, P=0.007) and NPS (NPS2: 19% vs. 3%, P=0.001). CD3+ density (P&lt;0.001), mGPS (P=0.01) and NPS (P=0.042) were associated with survival independent of MMR status (P=0.367) and stratified five-year survival of patients with MMR competent CRC from 94% to 67%, 83% to 46% and 78% to 60% respectively. CONCLUSION: MMR deficiency was associated with local and systemic environments, and compared with their assessment, dMMR had relatively poor prognostic value in patients with primary operable CRC. In addition to MMR status, local and systemic inflammatory responses should be assessed in these patients